Electric typewriter keyboard operated mechanism



A ril 23, 1968 R. J. JABLONSKI ET ELECTRIC TYPEWRITER KEYBOARD OPERATED MECHANISM 5 Sheets-Sheet 1 Filed May 5, 1967 INVENTORS. ARTHUR M PAS/NSK/ RICHARD J JABLO/VS/(l. MW ATTORNEY Fig. 2.

April 1968 R. J. JABLONSKI ET AL ELECTRIC TYPE-WRITER KEYBOARD OPERATED MECHANISM Filed May 5 6 Sheets-Sheet IN VE N TORS.

ARTHUR M PAS/NSKI. RICHARD J JABLONSKI. BY

ATTORNEY April 23, 1968 R. J. JABLOQSKI ET AL 3,379,297

ELECTRIC TYPEWRITER KEYBOARD OPERATED MECHANISM 5 Sheets-Sheet 3 Filed May 5, 1967- S/NSK/ JABLONS/(l.

INVENTORS. ARTHUR M PA RICHARD J.

M1 ATTORNEY.

United States Patent 3,379,297 ELECTRIC TYPEWRl'iER KEYBOARD OPERATED lWECI-IANISNI Richard J. Jablonski, Farmington, and Arthur M. Pasinski, Detroit, Mich., assignors to Burroughs Corporation,

Detroit, Mich, a corporation of Michigan Filed May 3, 1967, Ser. No. 635,715 10 Claims. (Cl. 19716) ABSTRACT OF THE DISCLOSURE by the printing operation. A normally tensioned flexure or leaf spring is released by a predetermined distance of depression of a key to activate the machine cycling switch whereupon the spring then functions as a latch to hold the interposer in effective position for operation by the cycling operation.

Summary of the invention The invention resides in the provision of the switch actuator-latch which is normally in overlapping relation to the free end of the interposer. The length of the overlap determines the distance that a key must be depressed in order to initiate a typing operation. When a key is depressed to the point where the switch actuator-latch is released, the actuator-latch flexes in a direction to set the machine cycle switch and at the same time latches the interposer in down position to insure that the type selective switch is set.

The problem which I have overcome is peculiar to electric typewriters of the kind in which a single, type carrying head, usually spheroidal in form, carries all of the type. As is well known, the head must be positionable either by rotating it or by tilting it or both to bring a type to print position and that this must be done by some kind of key selected interconnecting mechanism. In such machines of the past, an accidental slight depression of a key, commonly referred to as key flicking, would initiate a machine cycle of operation, but would not initiate the character selection mechanism. Obviously, a malfunction occurred since the ball printer had not been positioned and would therefore print the previously selected type character.

Accordingly, it is the principal object of my invention to obviate the above mentioned objection and to do so without detracting from the desired sensitivity or light touch characteristic of the keyboard.

In the drawings:

FIG. 1 is a side view of an electrically operated typewriter embodying features of the invention;

FIG. 2 is a vertical sectional view showing certain of the operating parts in their normal positions;

FIG. 3 is a view similar to FIG. 2, showing the operating parts in their effective positions;

FIG. 4 is a fragmentary detail view;

FIG. 5 is a cross sectional view, taken along the line 5-5 of FIG. 2;

FIG. 6 is a view similar to FIG. 5;

FIG. 7 is a fragmentary elevational view, taken in the direction of the arrows 7-7 of FIG. 2;

FIG. 8 is a fragmentary side view, and

3,379,297 Patented Apr. 23, 1968 FIG. 9 is a fragmentary side view of a modification.

Referring to the drawings, the typewriter includes a supporting means or keyboard frame comprising opposite side plates 10 and 12 rigidly connected together by cross rods in the well known manner. Positioned between the side plates 1.0 and 12 there is a plurality of laterally spaced apart key levers 14, only one of which is shown, pivotally mounted on a fixed transverse shaft 16. The levers are provided with the usual key tops 18, designating the different type characters. Near the front of the keyboard, each of the levers 14 is provided with a flexure or leaf spring 19 which abuts the free ends of the levers to return them to normal positions against a transverse stop mem- 'ber 20. Corresponding to each of the key levers 14 are individual key operated mechanisms which are alike; and, therefore, in the interests of simplicity and clarity, the description is limited to one such mechanism. A well known type carrier and platen striker 21 is of the spheroidal form and is positionable to bring a key selected type into printing position.

Directly below the key lever 14 there is an operator or interposer 22 which has a forwardly disposed end pivotally mounted on a fixed transverse shaft 23. To receive the shaft 23, a slot 24 is provided in the interposer 22 so that the latter is also longitudinally movable on the shaft 23. Normally, the interposer 22 is yieldably held in the position shown in FIG. 2, by a coil spring 25 having a lower end connected, as at 26, to the interposer 22 and an upper end anchored to a transverse rod 27. As shown, the spring 25 is arranged such that it exerts upward and rearward force components. A guide and stop member 28 for the interposer 22 has an upper inclined cam surface 29 which may be inclined at the same angle as the force line of the spring 25, which angle may be 45 degrees. Extending forwardly and downwardly, the angularity of the surface 29 changes to provide a lower cam surface 29 which is inclined to provide an acute angle with the angle of force of the spring 25. Normally, an abutment 33 on the interposer 22 is held in engagement with the upper cam surface 29 by the spring 25, as shown in FIG. 2. Thus, the components of force of the spring 25 hold the interposer 22 in its rearward position and upwardly against the upper cam surface 29. A switch 30, shown in FIGS. 5 and 6, is closed by forward movement of the interposer 22 and the switch is representative of a type character. The interconnecting mechanism between the switch and the ball printer is well known and is not shown for the additional reason that such interconnecting mechanism forms no part of the present invention. The switch 30 is illustrated in FIGS. 5 and 6 as comprising a pair of thin flexible contact members 31 and 32 of magnetizable sheet metal arranged with movable end portions in overlapping relationship. The contact members 31 and 32 are preferably enclosed by a sealed capsule 34. The contact members 31 and 32 are permanently magnetized such that they have similar negative polarization and, therefore, are normally parted, as shown. A permanent magnet 36 has one end normally overlying the overlapped end portions of the contact members 31 and 32 and the polarization of the permanent magnet is dissimilar to that of the contact members 31 and 32 whereby the contact members remain in parted relationship. The magnet 36 is carried by and at the lower end of a holder 38 which is affixed onto a r rotatable bail 40, the bail being rotatably mounted in suitable journals on the side plates of the machine. An offset portion 44 of the bail provides a crank arm and is engageable by a depending lug 45 of the interposer 22 when the latter is moved forwardly whereby the magnet 36 is angularly displaced to the position shown in dot and dash lines in FIG. 6. In this position of the magnet 36, its magnetic force is directed entirely to the switch contact 32 which is then attracted to engage contact 31. A torsion spring 47 of the bail 40 has one leg anchored and the other leg abutting the offset portion 44 of the crank, the torsion spring being adapted to return the bail to normal or home position, limited by a stop member 49.

Suitably journaled in the frame side members and 12 there is a driven camshaft 46 which is connectable by a one revolution clutch 48 to a drive shaft 49', as shown in FIG. 4, the clutch being activataole by a normally de'energized solenoid 50. A switch 51 has an operating plunger 52 which is normally biased to switch closed position and is restrained by a pivotal latch member or lever 54 by way of a connecting lever 56. The latching lever 54 is affixed to a rotatable transverse shaft 57. The lever 56 has an end of one arm 58 thereof engaging the switch plunger 52 and has another arm 60 which carrier a square stud 62 which normally engages in a notch 64, provided in the upper end of the latching lever 54. The lever 56 is pivoted on a fixed transverse shaft 63. A spring 66, attached to the arm 60 of the lever 56 urges the lever 56 in a counterclockwise direction, as viewed in FIG. 1, and a second spring 68 yieldably holds the latching lever 54 in latched position, as shown. Also afiixed onto the rotatable shaft 57 there is a lever 67 which extends upwardly from the shaft as shown in FIG. 2, having a horizontal flange 67 on its upper end on which an abutment 69 is rigidly secured.

Afiixed onto the driven shaft 46 there is a cam 70 having a cam surface engaged by a cam follower 72 on the free end of a lever 74 which has its other end affixed to a rotatable transverse shaft 76. The shaft 76 is journaled in the frame side plates 10 and 12, and affixed to the shaft 76 there is an interposer operating lever 77, shown in FIG. 2. Extending upwardly from the shaft 76, the lever 77 has an upper end 78 positioned to engage an abutment 79 on the interposer 22 after the free end of the latter has been depressed by the key lever 14. The lever 77 rotates clockwise to shift the interposer 22 to the right or forwardly to effect the closing of the switch member 52. Carried by and extending laterally from one side of the cam 70 there is a pair of angularly displaced rollers 82 which are positioned to engage the lower end of an arm 84 of the lever 56 and pivot the lever clockwise, as viewed in FIG. 1, to restore the lever 56 to latching relationship with the latching lever 54 and also to open the switch member 32. As previously mentioned, the switch member 32 is an electrical representation of a type character to be printed, and through well known interconnecting mechanism (not shown) causes the ball printer 21. to be positioned to bring the required type character to print position. Before the cam follower 72 leaves the high surface of the cam 70, the typing operation is effected, followed by a restoration of the keyboard operated parts to their positions of FIGS. 1 and 2.

In order to activate the switch 51 to effect a cycle of operation of the camshaft 46 in response to a depression of the key lever 14, I provide a latching actuator 86 in the form of a fiexure or leaf spring 86. An upper end of the leaf spring 86 is suitably secured or anchored to a bracket 88 and the lower end of the leaf spring overlies the free or rear end of the interposer 22. Normally, the rear end of the interposer 22 is in engagement with the leaf spring 86, and the coil spring 25 is urging the interposer re-arwardly, to hold the leaf spring flexed under tension. Also, the tensioned leaf spring 86 bears against the abutment 69 on the lever 67 and is operable when released to rotate the lever in a clockwise direction, as viewed in FIG. 2. A lower end portion 90 of the leaf spring 86 projects below the upper edge 92 of the interposer 22 and the length of said projection determines the distance which a machine operator must depress key lever 14 in order to free the leaf spring 86 to effect a machine cycle. When the key lever 14 is depressed, a depending abutment 94 carried thereby abuts an upstanding abutment 96 on the interposer 22. Preferably, the key lever abutment 94 is a pawl pivoted on the lever, as at 98 and urged counterclockwise against a stop member 100 by a coil spring 102. The pawl 94 is employed because it is possible for a machine operator to hold key lever 14 down while depressing another key lever which would place the pawl rearwardly of the interposer abutment 96. If this occurs, spring 25 overcomes the pawl spring 102 and pivots the pawl to allow the interposer to return to its normal or starting position, shown in FIG. 2.

Operation Upon the depression of the key lever 14, the pawl 94 abuts the top of the interposer abutment 96 and pivots the interposer about its fulcrum 23. If the depression distance is sufiicient such that the horizontal edge 92 of the interposer is pivoted below the lower end of the leaf spring 86, the spring is released and flexing forwardly rotates the lever 67 in a clockwise direction, as viewed in FIG. 2. At the same time that the lever 67 is being rotated, the lower end of the leaf spring 86 has moved over the edge 92 of the interposer 22 and has latched the interposer 22 down, as shown in FIG. 3. Rotation of the lever 67 by the leaf spring 86 rotates the shaft 57 and consequently the latching lever 54 in a clockwise direction which releases the square stud 62. This allows the interconnecting lever 56 to pivot counterclockwise, as viewed in FIG. 1, and release the plunger 52 to allow the switch 51 to close. The closing of the switch 51 energizes the solenoid 50 of FIG. 4 which then functions to activate the one revolution clutch 48 so as to drive the camshaft 46. Rotating in the direction of the arrow in FIG. 1, the cam 70 pivots the cam follower lever 74 in a clockwise direction which rotates shaft 76 in a like direction and, as will be seen in FIG. 2, the arm 77 is rotated to engage and shift the interposer 22 forwardly. As the interposer 22 is moved forwardly by the arm 77, the abutment 33, in engagement with the cam 29, causes the free end of the interposer to be moved downwardly against the component force of the spring 25 which tends to raise the free end of the interposer. In its forward movement the lug 45 of the interposer 22 engages the bail crank portion 44 and rocks the bail to swing the magnet 36 away from the flexible read switch member 32, allowing the latter to close. As this occurs, the rear end of the interposer 22 disengages from the leaf spring 86 at which time the lower cam surface 29' prevents upward movement of the free end of the interposer by the spring 25. The torsion spring 47 returns the interposer 22 during which the spring 25 holds the interposer abutment 33 against the cam surfaces 29', 29 to position the free end portion 92 of the interposer under the horizontal flange 67' and flex. spring 86, as shown in FIG. 2. When the interposer is being resest, arm 77 is being returned to open the switch 51 and latch the arm 77 in its retracted position.

As previously mentioned, the switch members 31, 32 are electrically representative of a type character and the closing of the switch initiates the operation of well known mechanism to position the ball printer 21 to print the type character selected. It will be seen that if a key is depressed to the point Where the spring latch member 86 is released, the machine cycling switch 51 will be closed and the interposer will be latched down until the character selection switch 31, 32 has been closed long enough to effect the positioning of the ball printer. While I have herein disclosed one key and associated mechanism, it will be understood that a typewriter will be provided with similar mechanism for each character key of the keyboard.

In FIG. 9 there is shown a modification of the machine cycle switch 51, the modified switch being designated generally by the numeral 104. The switch 104 includes a movable switch member 106 which is mounted on the resilient latch member 86' and is cooperable with a stationary contact member or bus 1% supported by the bracket 88'. A dielectric spacer lit) is provided between the latch member 86 and the switch member 106 to electrically insulate the switch member from the latch member. As shown, the interposer 22, in its normal position, is holding the latch member 86 under tension with the switch member 196 in open position. Thus, when the interposer 22 is pivoted downwardly by key depression, to the point where the latch member 86' will flex into position over the upper edge 92 of the interposer to latch the interposer in down position, the flexing of the latch will close the machine cycle switch N34 to energize the clutch solenoid 50'.

What is claimed is:

Electric typewriter mechanism comprising supporting means, a first switch member, cyclically operable means operatively connected to activatable by operation of said first switch member, a depressible key, a second switch member representative of a type carrier cor responding to said hey, an operating member pivoted on said supporting means and biased to a normally retracted position, said operating member pivotal by depression of said key, said operating member also mounted for movement by and upon operation of said cyclically operable means to activate said second switch member. and a resilient latching actuator operatively connected to said first switch member and normally restrained by said bias, said latching actuator being operable to flex and latch said operating member against the action of the bias by and upon a predetermined angular displacement of said opcrating member by said key, said first switch member beim operable by said latching actuator by and upon the latching of said operating member by said latching operator.

2. Electric typewriter mechanism as defined by claim 1 wherein the resilient actuator is a leaf spring normally in tensioned abutment with the free end of said operating member.

3. Electric typewriter mechanism as defined by claim. 1 wherein the resilient actuator is a leaf spring normally in tensioned abutment with the free end of said operating member with a free end portion of the spring overhanging the free end of the operating member in the direction of angular displacement of the latter.

4. Electric typewriter mechanism as defined by claim 1 wherein the leaf spring is fulcrumed above said operating member and depends into broadside relationship wi h the free end of said operating member, and a lower portion of said leaf spring extending below said operating member determining the distance of key depression necessary to release said spring into latching position above said operating member.

5. Electric typewriter mechanism as defined by claim 1 wherein a normally engaged latch normally restraining the closing of said first switch member is unlatched by and upon release of said resilient actuator.

6. Electric typewriter mechanism as defined by claim 1 wherein said first switch member is directly actuated by said resilient actuator.

7. Electric typewriter mechanism as defined by claim 1 wherein said first switch member is carried by said resilent actuator and moved to closed position by and upon the latching of said operating member by said resilient actuator.

8. Electric typewriter mechanism as defined by claim 1 additionally including a stop member overlying and normally engaged by a free end portion of said pivotal operating member, said operating member movable laterally out of the path of said stop member, and a guide member disposed laterally of said stop member and engaged by said operating member to guide the free end of the latter beneath said stop member when said operating member returns to said normally retracted position.

9. Electric typewriter mechanism as defined by claim 8 whelein said guide member is an inclined cam parallel with the direction of force of the bias.

10. Electric typewriter mechanism as defined by claim 9 wherein another cam contiguous with and below the first mentioned cam is disposed at an acute angle to the path of movement of said operating member to engage the free end of the latter and yieldingly oppose said bias.

References Cited UNITED STATES PATENTS 2,978,085 4/1961 Hickerson l97l6 3,086,635 4/1953 Palmer 197-l6 3,273,684 9/1966 Oshiba et al 19716 X ROBERT E. PULFREY, Primary Examiner. EDGAR S. BURR, Examiner. 

